1. Field of the Invention
The present invention relates to a magnetic disc apparatus, and in particular, to improvements of a hardware structure and a circuit structure of a magnetic disc apparatus that accomplishes a copy protect function.
2. Description of the Prior Art
Conventional magnetic discs do not have a copy protect function. The copy protect function is conventionally accomplished as a write protect function using a switch or a jumper disposed on a circuit board. The purpose of the write protect function is to prevent user data from being mistakenly destroyed with data that is written when it is restored from a magnetic disc that is defective. On the other hand, digital high quality data tends to be stored to a magnetic disc.
Digital high quality video data such as movies and video clips can be copied without a deterioration of the picture quality. Thus, from a view point of the copyright protection of digital contents, needs for copy-protecting digital high quality pictures are becoming strong To satisfy such needs, for example JPA 11-306648 (referred to as related art reference 1) discloses an information record medium having a copy protect function. According to the technology disclosed in the related art reference 1, an information record area for recording predetermined information and a trap area for causing a copying device to malfunction are formed so as to prevent all information including encrypted information recoded on an optical disc from being copied as it is.
In addition, JPA 61-206905 (referred to as related art reference No. 2) discloses a magnetic disc having a copy protect code. The magnetic disc of the related art reference 2 comprises (1) a magnetic disc device of which a magnetic disc is used as a record medium, (2) a magnetic disc device controlling circuit for generating a random number and recording the generated random number to the magnetic disc, and (3) a host system of which a magnetic disc device is used as a recording device. The magnetic disc has (1-1) an area for recording information received from a host system (this area is referred to as information area) and (1-2) an area for recording random number generated by the magnetic disc device controlling circuit (this area is referred to as random number area). When the host system records information to the information area of the magnetic disc, the magnetic disc device controlling circuit records a random number to the random number area while the host system records information to the information area of the magnetic disc. After they have been recorded, the random number that has been recorded in the random number area is read. The random number is recorded to a particular information area (second information area) different from the information area. When the information area is read from the magnetic disc, the random area is also read The relation between the random number recorded in the second information area and the random number that is read therefrom is verified.
However, in the technology of the related art reference 1, the trap area is formed at a particular position in such a manner that when an RF copy (disc copy) is attempted, the trap area prevents the disc copy from being performed. Thus, the technology of the related art reference 1 is limited to an optical disc of which data is spirally written. Consequently, the related art reference 1 cannot be applied to a magnetic disc of which tracks are recorded on concentric circles (namely, a hard disc drive).
In addition, according to the technology of the related art reference 1, although a copy operation using disc copy command can be prohibited, when data is read using read command and then the read data is written to a destination record medium, the data can be easily copied.
The technology of the related art referenced 2 is applied to a magnetic disc using servo-surface servo-system as a head aligning system for a magnetic disc. Thus, the technology of the related art reference 2 cannot be applied to a magnetic disc using the data-surface servo-system that has been widely used.
In addition, according to the technology of the related art reference 2, a check program for checking a protect code is recorded in a data area along with data. In this method, when data is read from a source magnetic disc sector by sector, rather than a file system level managed by the OS, and then the read data is written to a destination record medium, the data can be easily copied.
An object of the present invention is to provide a magnetic disc having a hardware structure and a circuit structure that accomplish a copy protect function.
According to a first aspect of the present invention, there is provided a magnetic disc device having a disc enclosure for enclosing: a magnetic disc medium on which data has been recorded; a circuit for processing a signal that has been read from the magnetic disc device, wherein a signal that is read from the magnetic disc is output from only an interface.
The magnetic disc device according to the first aspect may further comprise: a record medium on which a first authentication code has been recorded; an interface for inputting a second authentication code; collating means for collating the first authentication code with the second authentication code; and means for reading the data and outputting the read data to the outside only when the first authentication code matches the second authentication code.
The magnetic disc device according to the first aspect may further comprise: means for decreasing the number of times of a retry operation performed when a data read error takes whenever data is read from the magnetic disc medium.
The magnetic disc device according to the first aspect may further comprise: means for limiting the number of times that data is read from the magnetic disc medium.
According to a second aspect of the present invention, there is provided a magnetic disc medium on which data has been recorded, comprising: a record medium on which a first authentication code has been recorded; an interface for inputting a second authentication code; collating means for collating the first authentication code with the second authentication code; means for reading the data and outputting the read data to the outside only when the first authentication code matches the second authentication code.
According to a third aspect of the present invention, there is provided a magnetic disc device, comprising: a magnetic disc medium on which data has been recorded; and means for decreasing the number of times of a retry operation performed when a data read error takes place whenever the data is read from the magnetic disc medium.
According to a fourth aspect of the present invention, there is provided a magnetic disc device, comprising: a magnetic disc medium on which data has been recorded; and means for limiting the number of times that data is read from the magnetic disc medium.
These and other objects, features and advantages of the present invention will become more apparent in light of the following detailed description of the best mode embodiment thereof, as illustrated in the accompanying drawings.